Supervisory circuit for standby battery power supply - monitors battery current as circuit continuity check by use of bipolar relay

摘要

In a non-break power supply, a battery (11) is employed as a back up source to the main rectifier (2) providing power to the load (3). The presence of a circuit through the battery is continuously monitored by measuring the current in its circuit (1). A shunt (12) provides the input to a bipolar relay (12'). When only minimal current is flowing, that is with the battery charged, the relay drops off. Relay signals go through a time delay (13) to a control element (21) which reduces the main source voltage output slightly, and also to an AND-gate. A drop in voltage causes the battery to provide some of the load current and the relay picks up again, resetting both the controller and AND-gate. The cycle then recommences.